Per http://en.wikipedia.org/wiki/Iliotibial_band_syndrome :
“While pain can be acute to quite painful, the iliotibial band can be rested, iced, compressed and elevated (RICE) to reduce pain and inflammation, followed by stretching. Massage therapy may also be beneficial by removing the scar tissue. Using a foam roller to loosen the iliotibial band can help prevent and treat pain although the treatment itself can be very painful to some. Also, an ultra sound machine can be used around the area to relax it, followed by a machine that utilizes electrode stimulation to the area to further relax it. This can result in more comfort and/or a wider range of motion. Consulting with a doctor or referring to a registered physiotherapist or athletic therapist would be the best solutions. Custom foot orthotics may treat this condition by controlling the amount of inversion (medial rotation) of the foot and thus reducing rotation of the leg and knee (which creates friction of the Illiotibial Band against the outside of the knee).”